p-Toluenesulfonic acid → HCID 54254101, compound

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Reaction Steps

A solution of 1.89 g. of 1-isopropylsulfonyl-2-amino-6-(α-hydroxy-α-tert.-butoxycarbonylmethylbenzyl)benzimidazole (from Example 6) and 1.2 g. of p-toluenesulfonic acid in 100 ml. of chloroform was heated at reflux for two hours and then cooled to room temperature. The solution was extraced three times with aqueous sodium bicarbonate solution. The aqueous extracts were combined, washed with fresh chloroform and then neutralized to pH 7.0 by the addition of 1 N hydrochloric acid. The acidic solution next was extracted several times with ethyl acetate. The extracts were combined, washed with water and dried. Removal of the solvent by evaporation under reduced pressure provided 1-isopropylsulfonyl-2-amino-6-(α-hydroxycarbonylmethylenebenzyl)benzimidazole.

Provenance & Evidence